1. Field of the Invention
This invention relates to an improved rolling tarp enclosure system. More particularly, the invention relates to several improvements for a retractable tarp enclosure system which may be used for covering substantially any area or object, including swimming pools, beds of trucks, flatbed trailers and the like. More particularly, the present invention relates to such a rolling tarp enclosure system with improvements to a rail and rolling carriage arrangement thereof, to tensioning arrangements thereof, to corner portions of end sections thereof, and to other aspects of the rolling tarp enclosure system.
2. Discussion of Background Art
Rolling tarp covering and enclosure systems have long been known for use in a wide variety of applications, including tents, greenhouses and other space enclosures, awnings, swimming pool covers, vehicle load covers, etc. When such systems are provided on vehicles such as flatbed trailers, some aspects of the systems take on special significance, including appropriate tensioning of the tarp as disposed on the vehicle such that the tarp can sufficiently withstand external forces applied thereto while the vehicle is traveling, especially at high speed, the ability to keep water, dirt, and other foreign matter from entering inside of the tarp cover while the vehicle is traveling, the ability of the tarp system to extend at different levels along a vehicle surface which extends at the different levels, such as a so called “drop deck” flatbed trailer, etc.
A rolling tarp cover system will typically include wheeled carriages, skids, and/or other mechanisms which permit the cover system to be moved to various positions, and may include a drive assembly for facilitating the movement of the tarp cover rather than manually pushing or pulling it to a desired position. Also, a movable tarp cover system will typically include mechanism(s) for securing or locking the cover system in various positions, such as a fully closed or covering position and a fully retracted or non-covering position, and will also typically include mechanism(s) for tensioning the tarp cover when it is disposed in a fully covering position thereof for improved aerodynamics, appearance and durability. Some of the known tarp tensioning mechanisms are structurally associated with the mechanisms which permit the cover system to be moved and some are not.
Applicant has previously proposed several cover systems which may, for example, be used for covering loads on flatbed trucks/trailers as a so-called rolling type tarpaulin system, see for example U.S. Pat. Nos. 5,924,759, 7,854,465, and 8,047,600. These prior systems include a plurality of inverted U-shaped bows supporting a flexible cover, and rails provided along opposite sides of the truck bed which support ends of the bows through wheeled carriages such that the tarp cover may be easily moved longitudinally along the bed permitting the tarp to be extended over the bed or collapsed in an accordion-like manner, as well as locking mechanisms for the two ends of the tarp enclosure which also permit the tarp enclosure to be tensioned at either/both ends. The disclosures of U.S. Pat. Nos. 5,924,759, 7,854,465, and 8,047,600 are incorporated herein by reference.
While the conventional cover systems, including those previous systems proposed by applicant, are generally effective for their intended purposes, the conventional systems remain to be improved upon in various aspects thereof.
Rear Locking and Tensioning Mechanisms
In many truck mounted rolling type tarpaulin systems there is typically provided some type of locking and tensioning mechanism associated with the rear end of the system, whereby when the system is in its fully covering position and the front bow is locked in position, e.g., in engagement with the headboard at the front of the truck trailer, the tarp cover can be stretched tight by moving the rearmost supporting bow rearwardly a few inches. In the applicant's previously proposed systems in U.S. Pat. Nos. 7,854,465 and 8,047,600, there is disclosed a conventional tensioning and locking mechanism for the rear end of the cover system, which is shown in FIG. 7A thereof. The previously proposed system includes a movable catch provided with a rotatable screw rod, which catch engages and selectively moves a rearmost rolling carriage, which is operatively connected to a rear end of the tarp cover, rearwardly so as to tension the tarp cover and to lock the rearmost rolling carriage in the tensioned position. The catch is movable in the longitudinal direction of the cover system by cranking the rotatable screw rod. Another tensioning mechanism for rolling type tarp cover systems is known under the name “Loc-N-Load Mechanism”, one example of which is disclosed in U.S. Pat. No. 7,798,553.
While such previously disclosed tensioning mechanisms function appropriately for tensioning the tarp cover, they have limitations associated therewith. For example, while the applicant's prior locking tensioning mechanism in U.S. Pat. Nos. 7,854,465 and 8,047,600 functions appropriately to tension the tarp cover, it only engages the rearmost carriage at the bottom portion of the tarp cover which makes it somewhat challenging to tension the tarp cover fully to the upper end thereof. Also, when the rearmost supporting bow is fully tensioned, it may have a slight tilt to the vertical axis. This is acceptable, but some additional means should be provided to prevent any undue or unbalanced forces from being applied to the wheels of the rearmost rolling carriage because undue or unbalanced forces would significantly shorten the useful life of the wheels.
Regarding the Loc-N-Load Mechanism, this is specifically designed for rolling tarp cover systems having rolling carriages with wheels disposed inside of a rail along which the carriages move because the Loc-N-Load Mechanism is disposed directly above the rail. Conversely, the applicant's rolling tarp system, commercially sold under the trademark Quick Draw™, has rolling carriages with wheels that roll along the top of the rail, and hence cannot use the Loc-N-Load Mechanism because it would interfere with movements of the rearmost rolling carriage.
Applicant has also previously proposed another type of locking and tensioning mechanism for the rear end of a truck mounted rolling tarp cover system as disclosed in relation to FIG. 11 of U.S. Pat. Nos. 7,854,465 and 8,047,600, as well as in present FIG. 7. This other type of mechanism, which is also disposed inwardly of the tarp cover at a rear portion thereof, is generally triangular in shape and functions to better and more uniformly tension the tarp cover in comparison to the prior mechanism shown in FIG. 7A of the prior patents because it applies the rearward tensioning forces to a vertically intermediate portion of the rear bow which supports the tarp cover.
Applicant's previous mechanism 100 is generally triangular in shape, attaches to the floor of the flatbed trailer, has a rearward facing hook 102 at its upper end which engages an projection or puck fixed to and extending inward of a vertically intermediate portion of the rear bow, and includes a moveable portion including a rotatable screw rod which, when rotated, moves the hook for thereby locking and tensioning the rear bow relative to the trailer. The mechanism includes a lower horizontal leg 108 which is also the rotatable screw rod, a vertical leg 105, a diagonal leg 106, a first bracket 104 and a second bracket 104′ all connected together in the generally triangular shape. The first and second brackets rotatably receive and support opposite end portions of the lower leg 108, and are operatively secured to the flatbed trailer, whereby an operator may rotate the lower leg 108 with a crank handle 107 or the like engaged to a rear end of the lower leg 108 for thereby moving the hook 102 to a desired position.
The first bracket 104 is fixed to the flatbed trailer at a specific locations near the rear end of the lower leg 108, while the second bracket 104′ is connected to the flatbed trailer such that it may move linearly relative to the trailer in the front-rear direction. The second bracket 104′ includes a threaded nut that receives a threaded front section of the lower leg 108 therethrough. Rotation of the lower leg 108 causes the second bracket 104′ to move along the threaded front section of the lower leg 108, and correspondingly the lower end of the diagonal leg 106, which is pivotally connected to the second bracket 104′ also moves along the threaded front section of the lower leg 108. This in turn causes the hook 102 at the upper ends of the diagonal leg 106 and the vertical leg 105 to move in an arc pattern, which due to engagement of the hook 102 to the intermediate portion of the rear bow, also moves the rear bow in the front-rear direction, and to a lesser extent in the up-down direction. For example, for tensioning the tarp cover the lower leg may be rotated clockwise which moves the second bracket 104′ closer to the first bracket 104. The diagonal arm 106 and vertical arm 105 are thereby rotated rearward, which moves the hook 102 and the rear bow it engages rearward thereby tensioning the tarp cover. At this time the hook 102 and rear bow are also moved slightly upward, which also lifts the rolling carriages connected to lower ends of the rear bow slightly upward. This is very advantageous because the main wheels of the rearmost carriages are thereby lifted off of the rail, preventing any load or stress from being applied to the wheels when the tarp cover is in a tensioned state, and greatly extends the life of the wheels.
The previous system allows for several inches of tensioning distance which is generally sufficient for producing sufficiently high tension on the tarp for full size truck and trailer applications over the life of the tarp system, even as the tarp cover stretches somewhat over time, and because the wheels of the rearmost carriage are lifted off the rail no undue pressure is applied thereto. This previous system can be easily operated from ground level and is located inside the tarp system to maintain aerodynamics and aesthetics of the system and vehicle.
Again, this locking and tensioning mechanism 100 previously proposed by the applicant is very effective for properly locking and tensioning the tarp cover. However, it also has some limitations associated therewith. For example, it must be precisely positioned relative to the puck connected to the intermediate portion of the rear bow for properly tensioning same. This creates some difficulties during initial installation of locking and tensioning mechanism, as well as throughout the life of the tarp cover system as it may become necessary for a driver to remove and re-install, or reposition the locking and tensioning mechanism on location wherever the trailer may be disposed at any given time. This complicates the work required by persons installing and operating the system, and may lead to safety issues if done too hastily or otherwise improperly. Also, while the mechanism is relatively compact it does project into the cargo space of a flatbed trailer more than the mechanism shown in FIG. 7A of U.S. Pat. Nos. 7,854,465 and 8,047,600.
Generally, each of the applicant's prior locking and tensioning mechanisms is sufficient for properly locking and tensioning a tarp cover system when used in pairs, e.g., a pair of the mechanism shown in FIG. 7A of the prior patents are provided in association with the rearmost carriages supporting legs of the rearmost bow on opposite sides of the flatbed trailer, or a pair of the mechanism 100 shown in FIG. 7 herein are provided in association with the supporting legs of the rearmost bow on opposite sides of the flatbed trailer.
Drop Deck Flatbed Trailers
Some flatbed trailers have portions which extend at different levels, e.g., a middle portion of the flatbed is disposed at a lower level than one or both ends of the flatbed. Such flatbed trailers may also be equipped with rolling type tarp cover systems, but such systems have conventionally required a second section of rail for being disposed at the higher level and extra rolling carriages for rolling on the second section of rail at the higher level, and/or other modifications in order to permit the tarp cover to be fully moved in the front or rear direction, which significantly increases the cost of the system. Also, the second section of rail may interfere with some movements of the system.
Rolling Carriages and Support Rails for Same
The applicant's commercial version of its rolling tarp cover system sold under the trademark Quick Draw™ has rolling carriages with wheels that roll along the top of the rail, details of which are explained in U.S. Pat. No. 5,924,759, whereas most other types of commercially available rolling type tarp cover systems having rolling carriages with wheels that are disposed within the rail. The rolling carriages with wheels that roll on top of the rail are typically more advantageous than the rolling carriages with wheels disposed within the rail for various reasons, including no restriction on size of the wheels for increased load capacity and durability. Even with the rolling carriages with wheels that roll on top of the rail, however, there are practical limits on the size and durability of same. Also, some rolling tarp systems are quite large and/or exposed to particularly significant external forces during use, such that there is a desire for a rolling carriage that can be reliably used with the larger systems and with systems that are exposed to particularly significant external forces during use.
Generally, the wheeled carriages, which are formed primarily of steel plates welded or otherwise connected together, together with the main wheels (whether they ride on top of the rail or inside of the rail) and other smaller wheels which provide stability of the carriages as they roll along the rails, constitute a primary portion of the tarp cover system, and the industry is always looking for manners of improving the carriages in terms of durability, cost, weight, and/or maintainability.
Further, with the vehicle-mounted rolling tarp systems there is often a need for additionally securing the cargo disposed on the flatbed trailer within the rolling tarp system, e.g., if the cargo's weight and/or shape tends to make it unstable. For such purpose additional mechanisms for securing the cargo may be provided, but it is typically necessary that any such mechanisms must disposed be inside of the tarp cover in order to maintain integrity of the tarp cover system when disposed in the fully covering position thereof, and also because government regulations strictly limit the size/width the rolling tarp systems. Disposition of the additional securing mechanisms within the tarp cover system, however, undesirably reduces the amount of usable cargo space within the tarp cover systems. Hence, there is a need for an additional securing mechanism which can be appropriately used with the rolling tarp cover systems, but which minimally reduce the amount of usable cargo space within the tarp cover systems and meet government regulations.
Support Bows and Lifter Bows
Referring to FIG. 11 of the present drawings there is shown a flatbed trailer having a rolling tarp cover system 1 disposed thereon according to a system previously proposed by the present applicant, with a portion of the tarp cover broken away to show details of the support bows and lifter bows of the system. The depicted system includes support bows 114 and lifter bows 112, with one support bow and two lifter bows having lower ends thereof supported by the wheeled carriages 16 that roll along the rails 4 of the system. Alternatively, the system may include four of the lifter bows having ends supported by each of the wheeled carriages, with two of the lifter bows on each side of the support bow.
The support bows 114 provide the main support for the tarp cover and have a much more rugged construction than the lifter bows 112 which function to keep the top portion of the tarp cover from sagging between the support bows when the cover system is in its fully deployed, covering position. The vertically extending ends of the support bows are fixed to longitudinally intermediate portions of the wheeled carriages 16, while lower extending ends of the lifter bows 112 are pivotally connected to the wheeled carriages 16 on opposite sides of the support bows 114 so that the lifter bows can be moved away from the support bows when the tarp cover is extended and moved adjacent to the support bows when the tarp cover is collapsed.
The tarp cover of the system may be formed in sections rather than as one large continuous member for ease of handling and maintenance, with adjacent sections of the tarp cover being joined together where they are connected to the support bows 114 such that the tarp cover appears to be one continuous member. On the other hand, the lifter bows 112 may have upper, longitudinally extending portions thereof connected to the tarp cover at positions intermediate two adjacent ones of the supporting bows 114 using hook-and-loop fasteners or the like, so that the lifter bows are automatically disposed adjacent the support bows when the tarp cover is in a collapsed position thereof, and automatically moved away from the support bows as the tarp cover is moved to its fully deployed or covering position so that they prevent the tarp cover from sagging at positions between the support bows when in the fully deployed position.
While the previously proposed system including such support bows 114 and lifter bows 112 functions very well in supporting the tarp cover in the applicant's previously proposed system, the cost of same is significant. For example, with reference to FIG. 12 of the present drawings, the applicant's current commercial system, sold under the name of QUICK DRAW™ include a heavy duty corner section 116 for its support bows including two mating halves which are generally triangular in shape, die cast from aluminum and fastened together in surrounding relation to the ends of vertical and horizontal sections 92 of the bow that come together in the corner using bolts (not shown) which extend through openings formed in inwardly projecting web portions 116′ of the mating halves. Further, and with reference to FIG. 13 of the present drawings, the lifter bows of the applicant's commercial system include vertical and horizontal portions formed in straight sections of aluminum tubing 93, with plastic corner members 118 that connect vertical and horizontal straight sections of the aluminum tubing sections 93 that come together in the corner such as shown, and ends of the vertical sections of aluminum tubing 93 are connected to pivoting plastic members provided on the wheeled carriages by having the plastic members inserted into the ends. For example, the plastic corner members 118 may include a pair of elongate, curved plastic members 120 associated with a pair of the lifter bows 112, each of which has opposite ends 120′ with an outer diameter slightly smaller than the inner diameter of the sections of the aluminum tubing 93 so that the ends of the tubing may be securely fitted over the ends 120′ via friction engagement, and each corner member 118 includes an intermediate pivot connection 119 that connects the pair of plastic members 120 near ends thereof and permits the pair of lifter bows 112 joined by the corner member 118 to pivot toward and away from each other when the tarp cover is collapsed and extended. Hence, the applicant has investigated manners of reducing the cost of same, while still achieving appropriate functionality and durability.
As will be understood from the foregoing, a need still exists in the art for an improved rolling type tarp cover system which addresses and overcomes the above-discussed limitations and disadvantages of the conventional rolling type tarp cover systems.